Van: 96 e250 5.8L v8 automatic.

Story: My bolts for my exhauset manifold get loose over time and I just tighten them every few weeks when I notice the engine starting to run slightly rough. (I know I should just replace them) 1 of them has been broken for a few months though with out any noticable change in performance.

A few days ago on a 4 hour drive to work my engine started running very rough like it's missing on on of the cylinders. I noticed it about 3 hours in on my drive. It had just started raining and rained the rest of the trip. If feels like I'm driving down a rumble strip with the vibration in the gas peddle to. I checked the bolts that normally get loose and found a 2nd one is broken. (both broken bolts are on the passenger side but on different cylinders. It was night, in the middle of nowere so I limped it along to get to work.

Question: Would an exhaust leak like that from 2 broken exhaust manifod bolts cause the engine to misfire like that? Or cause bad pre-ignition/detonation? There's no noticeable gap between the manifold and block. My other thought is maybe with the exhaust leak the o2 sensor got dirty enough or went bad.

Or could it be the worst case senario for me that the engine sucked cold air into the exhaust leak anc cold air cracked a valve?

Any ideas?

 

Well its like this; Leaking exhaust manifold will burn up anything in the path of the leak, wires, hoses, metal pipes, etc. A long term leak will burn off the heads softer exhaust flange surface and will never seal up again, so then you need new heads and exhaust manifolds. As an old (motorhome nut) I hear a small block with leaking manifolds I know that engine is done at any milage! Good Luck...........